Citazione APA

Bir, S. S. (1983). Pterido phytes. Today and Tomarrow's Printers and Publishers.

Stile di citazione Chicago

Bir, S S. Pterido Phytes. New Delhi: Today and Tomarrow's Printers and Publishers, 1983.

Citazione MLA

Bir, S S. Pterido Phytes. Today and Tomarrow's Printers and Publishers, 1983.